title: Effect of endothelin inhibition on lung fibroblasts on patients with systemic sclerosis.
abstract: OBJECTIVE
  The aim of the study was to investigate the effect of selective ETRA Sitaxsentan on viability and differentiation into myofibroblasts of lung fibroblasts derived from SSc-ILD patients and the ability of this drug to modify the lung fibroblast synthesis of VEGF, type I collagen and fibronectin.
  
  
  METHODS
  Primary human lung fibroblast cultures were obtained from BAL of SSc-ILD patients. Cell cultures were exposed for 48 h to crescent concentrations of Sitaxsentan (10 -6M to 10 -4M). In these experimental conditions we evaluated cell viability through crystal violet staining, the production and mRNA expression of VEGF, fibronectin and type I collagen respectively through ELISA and real-Time PCR. Further, we detected alpha-Smooth Muscle Actin (α-SMA) through immunocytochemical assay.
  
  
  RESULTS
  The lowest concentration of sitaxsentan (10-6M) did not affect fibroblasts viability; conversely at higher concentrations, sitaxsentan induced a significant inhibition of cell viability. Synthesis and mRNA expression of VEGF, type 1 collagen and fibronectin were significantly reduced in treated lung fibroblasts compared to the untreated ones, in a dose-dependent manner. At higher concentrations, Sitaxsentan reduced the expression of α-SMA.
  
  
  CONCLUSIONS
  The results of this study show that sitaxentan is able in vitro to reduce both cell viability than production of VEGF and extra-cellular matrix components in SSc lung fibroblasts, confirming the anti-fibrotic potential of ETRA in SSc. The decreased expression of α-SMA in treated cells indicate that sitaxsentan may inhibit the fibroblast differentiation toward a myo-fibroblast phenotype and further support the hypothesis that the selective ETRAs may be beneficial in patients with SSc-ILD as anti fibrotic agents.
authors.affiliation: Rheumatology Clinic Department of Medical and Surgical Sciences University of Foggia, Foggia, Italy - fp.cantatore@unifg.it.
authors.forename: A
authors.initials: A
authors.lastname: Corrado
authors.forename: A
authors.initials: A
authors.lastname: Neve
authors.forename: E
authors.initials: E
authors.lastname: Costantino
authors.forename: G P
authors.initials: GP
authors.lastname: Palladino
authors.forename: M P
authors.initials: MP
authors.lastname: Foschino Barbaro
authors.forename: F P
authors.initials: FP
authors.lastname: Cantatore
mesh_terms: D000199:Actins / Q000378:metabolism; D000328:Adult; D000368:Aged; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D024042:Collagen Type I / Q000096:biosynthesis; D065128:Endothelin Receptor Antagonists; D016232:Endothelins / Q000037:antagonists & inhibitors*; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005353:Fibronectins / Q000096:biosynthesis; D006801:Humans; D007555:Isoxazoles / Q000494:pharmacology*; D008168:Lung / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000378:metabolism; D058628:Myofibroblasts / Q000166:cytology; D012595:Scleroderma, Systemic / Q000473:pathology*; D013876:Thiophenes / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis
chemical_list: D000199:Actins; D024042:Collagen Type I; D065128:Endothelin Receptor Antagonists; D016232:Endothelins; D005353:Fibronectins; D007555:Isoxazoles; D013876:Thiophenes; D042461:Vascular Endothelial Growth Factor A; C106276:sitaxsentan